1. Field of the Invention
The invention relates to a carbon film resistor having a non-conducting substrate provided with a carbon film, a top coating of inorganic material, an electrically insulating layer and electrodes which contact the carbon film.
2. Description of the Prior Art
U.S. Pat. No. 3,244,559 discloses a carbon film resistor of this type. With this carbon film resistor the electrically insulating layer which may, for example, consist of a glass coating or encapsulation, hermetically seals the subjacent carbon film with top coating. With this prior art carbon film resistor the top coating consists of a high-melting metal oxide obtained by decomposing an organic compound. The coating or encapsulation of glass is necessary because the top coating of a high-melting oxide, for example, silicon dioxide, after the resistance has been brought to the desired value by locally removing, scoring etc. of the carbon film no longer protects the side faces of the carbon film then exposed from attack by the atmosphere.